This invention relates generally to the field of cartridge loading apparatus, and, more specifically, to the motorized loading and/or unloading of data storage cartridges or cassettes from data storage drives or stations.
Cartridge loading apparatus for data storage cartridges or cassettes may be employed with automated data storage libraries, with multi-cartridge magazines, and with single cartridge mechanisms, and to accept manually provided cartridges. Cartridges may, for example, comprise a single reel wound with magnetic tape, dual reel cassettes of magnetic tape, one or more optical disks, magnetic disks or disks mounted on a rotatable shaft, completely encased magnetic disk drives, etc. Herein, all are termed xe2x80x9ccartridgesxe2x80x9d.
Such cartridge loading apparatus is typically expected to properly position the cartridge, and to provide the necessary pressure(s) to properly place and hold the cartridge, both as loaded and in position for unloading.
Hence, loaders are typically complex and precision mechanisms. U.S. Pat. No. 5,264,974 shows a cassette loading system with a motor and a plurality of cassette drive wheels and an engagement assembly. The patent shows a cassette drive wheel gear train, timing belt, and orientation sensor, and an engagement assembly with an engagement solenoid, two link plates having a narrow slot fixed to the solenoid piston, each with a bell crank rotatably attached to the link plate, a swing arm to which a drive wheel is rotatably mounted, and planetary gear shaft extending through the narrow slot so that the shaft is free to slide within the slot on the link plate. U.S. Pat. No. 3,811,625 shows a cassette-engaging structure with spaced apart jaws to engage the cartridge, one jaw including an extension which receives guide pins from a parallel gripping beam operated through a bell crank by a solenoid, and a spring is provided to release the cartridge upon deenergization of the solenoid. The positioning of the cassette is accomplished by a mechanism with a locking arm supported on a vertical pivot pin and another solenoid swings the arm to the tape deck, and is operated by a motor coupled through a pulley-belt apparatus to a rotatably mounted shaft with a Geneva movement and an axial cam, and employs shafts, pins, slots, riding surfaces, cams and springs.
Loading mechanisms for automated data storage libraries have the additional need to withstand impacts and pushing or pulling actions by the mechanism providing the cartridge to the loader. This is typically accomplished by providing restraint mechanisms with unidirectional springs (tension or compression) and/or by maintaining energization of the motor of the loader to hold the cartridge in a desired position when loaded. When a receiver for the cartridge is positioned in an unloaded position to allow the removal or delivery of a cartridge, typically no spring is provided, and the receiver for the cartridge is subject to creep, and may not be in the precisely correct position to accept a cartridge being delivered, requiring a level of xe2x80x9chuntingxe2x80x9d, or extra insertion effort by the delivering mechanism.
Restraining mechanisms for cassettes, respectively in a magazine and in a storage shelf, are shown in U.S. Pat. Nos. 5,936,795, and 4,772,968 with unidirectional bias springs and detents. Forces in the direction not offset by the bias of the springs are directly transmitted between the cassettes and the mechanism.
An object of the present invention is to provide a more simplified mechanism for a cartridge loading apparatus.
Another object of the present invention is to provide an apparatus tending to lock an engaged cartridge at a fully loaded position.
A compliant linkage is disclosed for a cartridge loading apparatus. The cartridge loading apparatus has at least one movable member for moving an engaged cartridge. One example is an arm with a pin which engages a notch of a cartridge. A reversible motor apparatus operates the cartridge loading apparatus.
The compliant linkage comprises at least one compliant link which has a longitudinal leaf spring resilient beam, and an arm extending laterally of the longitudinal beam in a direction such that rotational torque at the laterally extending arm tends to flex the longitudinal beam. The laterally extending arm is positioned towards a first end of the beam, forming, in one example, an xe2x80x9cLxe2x80x9d shape.
The longitudinal beam has a coupling axis toward a second end of the longitudinal beam opposite the first end; and the laterally extending arm has a coupling axis spaced from the longitudinal beam. The beam coupling axis and the arm coupling axis are parallel to each other and perpendicular to a plane formed by the longitudinal beam and the laterally extending arm. The compliant link is coupled to the movable member and to the reversible motor apparatus at respective ones of the coupling axes.
In this manner, application of a compression force to the compliant linkage provides a rotational torque at the laterally extending arm, which tends to reduce the distance between the coupling axes and to flex the longitudinal beam outwardly in a direction away from a straight line between the coupling axes; and application of a tension force to the compliant linkage provides a rotational torque at the laterally extending arm tending to increase the distance between the coupling axes and to flex the longitudinal beam inwardly in a direction towards a straight line between the coupling axes.
In another embodiment, the compliant link has two laterally extending arms, each at opposite ends of the longitudinal leaf spring resilient beam, in one example, forming a xe2x80x9cUxe2x80x9d shape. The coupling axes are spaced from the longitudinal beam such that the compression force and tension force provide the respective rotational torque.
In a further embodiment, a rotatable mechanism is coupled to the reversible motor apparatus, which is rotatable to an over-center position which is beyond the point at which the least one movable member and the at least one compliant link are moved to a fully loaded position at which an engaged cartridge is fully loaded at the receptacle. A xe2x80x9cloadedxe2x80x9d limit stop limits movement of the cartridge loading apparatus at the over-center position of the rotatable mechanism, such that a compression relationship is provided between the receptacle and an engaged fully loaded cartridge, which generates a tension force on the compliant link and tends to force the cartridge loading apparatus against the xe2x80x9cloadedxe2x80x9d limit stop, thereby tending to lock the engaged cartridge at the fully loaded position.